Vehicle vacuum brake



' www@ Oct' 4 1927 J. R BARHOLOMEW VEHI CLE VACUUM BRAKE Filed Feb. 8, 1926 NVENTOR` JOHNVRBARTHOLOMEW ATTO RNEY Patented ct. 4, 1927..

JOHN R. BARTHOLOMEW', OF MONTCLAIR, NEW JERSEY, ASSIGNOR TO THE WESTING- HOUSE AIR BRAKE COMPANY, OF WILMERD-IN G, PENNSYLVANIA,

0F PENNSYLVANIA.

Application led February This invent-ion relates to automotive brakes, and more particularly to a brake of the type in which the opposite sides of the brake piston are normallysubject to a vacuum and the brakes are applied by letting air valved hose coupling employed in connec-y tion with my invention.

The truck brake equipment shown inl Fig. 1 comprises a brake cylinder l containing a brake cylinder piston 2 which is connected to a pull rod 3 by piston stem 4, the pull rod 3 being connected to the usual brakemechanismI so as to apply the brakes when the piston stem 4 is pulled toward the left by the piston 2. A pipe 5 opens into brake cylinder 1 at one side of piston 2 and is connected to a vacuum source, preferably the suction ntake pipe 6 of an internal combustion engine 7. The opposite Aside of the brake cylinder 1 is .connected to a pipe 8 which leads to a 'hand operated control valve device 9. The valve device 9 contains a valve 10 adapted to be operated by a handle 11 and having coupling 16, With pipe 8 on the truck.

The `brake cylinder 1', at the opposite side of the vpiston 2, is connected to a pipe 17. The pipe 17 is connected through a flexible hose 18 with a pipe 19 which is connected to pipe 5. For'connecting the flexible hose sections between the truck and the trailer, a coupling is provided, as shown in Fig. 2, comprising coupling heads 20, having locking ribs 21 and 22 adapted to engage when A CORPORATION VEHICLE VACUUM BRAKE.

8, 1926. Serial N0. 86,763.

the two coupling heads are rotated, so as to lock the heads in engagement.

Each coupling head contains a movable member 23, having a stem 24 which is adapted to project through the opening of the gasket 25. 27 is pivotally mounted and one arm of the bell crank is connected to the member 23. The other arm is connected to a valve 28, which controls communication through the hose section 18. When-the coupling heads $5 are connected together, the engagement of tlie stems 24 causes the outward movement "of the members 23, so that lthe bell cranks 27 are loperated to unseat the valves 28.

When the; coupling heads are separated, the

springs 29 shift the members so' that the bell cranks 27 operate to seat the valves 28.

In operation, when the engine 7 is running, a vacuum is created in the intake pipe 6 and a similar vacuum is created on op- 75 posite/sides of the piston 2, when the valve 10 isin the position shown in the'drawing. The piston 2 on the trailer is also subjected to a vacuum on its opposite sides, since the pipes 8 and 17 areconnected to corre- 80 sponding sides of the brake cylinder piston 2 on the truck.

lf it is desired to apply the brakes, the handle 11 is turned so as tomove the valve 10 to the position in which pipe 8 is cone5 neeted to the atmospheric port 14. Air at atmospheric pressure is then admitted to the right hand side of the brake cylinder piston 2, as Well .as to the right hand side of the brake cylinder piston 2 on the trailer, and 9o trailer, While air from the atmosphere will enter the pipe 8', due to the separation of the coupling 16, so that the brake will be applied on the trailer. Y

0n the truck, the valve 28 of the truck coupling head will also close, so-that the vacuum is maintained on the left hand side ot' the brake cylinder piston 2 and the brakes may then be applied on the truck, if the han- In a chamber 26, `a bell crank 80 at opposite sides of said piston, separable dle 11 is turned to the position in lwhich 'pipe 8 is cut ofi from communication with pipe 13. i

It will be evident that the brakes on any number of trailers may be operated the same as in the case of the single trailer above described.

vThe construction described may also be employed to operate the brakes on the front wheels as Well as the rear wheels of. a inotor vehicle.

Having now `described my invention, what I claim as new and desire to secure by Letters Patent, is

1. The combination With a brake cylinder containing a brake cylinder piston, of piping connected to the brake cylinder chambers at opposite sides of said piston, means for maintaining a vacuum through said piping at opposite sides of said piston, and means associated with said piping and operated upon separation of the piping for holding the vacuum at one side and admitting air from the atmosphere vto the other side of said piston.

2. The combination with a brake cylinder containing a brake cylinder piston, of piping connected to the brake cylinder chambers yat opposite sides of said piston, meansfor maintaining a vacuum through said piping couplings in said piping, and means associated with the separable coupling in the piping leading-to one side of said piston for preventing the loss'of the vacuum from said side upon separation of the couplings.

3 The combination with a brake cylinder containing a brake cylinder piston, of a pipe connected to the brake cylinder chamber at opposite sides of said piston, a separable coupling in each pipe, and a valve in one of said couplings for closing communication through the corresponding pipe upon separation of the couplings. v 4. In a vacuum brake, the combination with a vacuum creating source and a brake cylinder containing a brake cylinder piston, of a manually operable valve having a position for connecting the brake cylinder charnbers at the opposite sides of said piston to said source, an additional brake cylinder containing a brake cylinder piston, pipes connecting .corresponding chambers of said brake cylinders, separable couplings in each pipe, and valves inthe coupling in one pipe operated upon separation of the couplings for preventing loss of vacuum through said pipe. Y

In testimony -whereof Ihave hereunto set my hand.

JOHN R. BARTHOLOM'EVV.v 

